The forming process as well blown extrusion and foaming of PLA and its blends was investigated in this study as an alternative for the production of food packaging. Through this work, we present some promising routes to enhance its processing ability which presents several challenges mainly due to the poor shear and elongation properties of this biopolymer. Two main routes were selected: (i) the modification of neat PLA structure, rheological and thermo-mechanical properties and (ii) blending it with other ductile thermoplastic biopolymer such as the poly (butylene adipate-co-terephtalate) (PBAT). To achieve this objective, various formulations of PLA and its blends based on PBAT with multifunctionalized epoxy, nucleants and plasticizer were prepared and characterized on the basis of their linear viscoelasticity, extensional properties and interfacial properties of blends was investigated systematically. The balance of chain extension and branching has also been investigated using physico-chemical analysis and rheology (Shear and elongation rheology, relaxation spectrum, Van Gurp Palmen curves….). We pushed further by characterizing both the structure and thermo-mechanical properties of PLA formulations. On one hand, a batch foaming assisted with supercritical CO2 was achieved. The influence of the foaming parameters, the extent of chain modification as well as the contribution of crystallization on cell morphology was evaluated. On the other hand, the stability maps of blown processing for modified PLA and its blends were established. We have achieved a great enhancement of the blown processing windows of PLA and compatiblized PLA/ PBAT blends. We were able to demonstrate that a higher kinetic of crystallization can also be reached for chain-extended and branched PLA formulated with adequate amounts of nucleants and plasticizers. Induced crystallization during process was also demonstrated.Films with interesting thermo-mechanical properties.